1. Field of the invention
This invention relates to electro-optical measurement apparatus for dimensional measurement of a wide range of components.
2. Background prior art
U.S. Pat. No. 4,747,689 discloses a computer controlled optical measurement apparatus for determining a plurality of dimensions of an object at linearly spaced locations on the object, comprising a measurement station for measurement of a linear dimension of the object, means to move the object through the measurement station to present the locations to be measured one by one, a light source on one side of the measurement station to direct a beam of light at the location of the object in the measuring station transversely to the required line of measurement and to the path of movement of the object through the station, elongate photo-electric array means disposed on the opposite side of the measurement station to the light source and lens means to focus an image of the part of the object to be measured on the photo-electric array means to form an image thereon of said part of the object. An elongate measurement graticule is provided on which a scale is delineated and means are provided for directing collimated light through the graticule and thence into the lens system to be focused on to the photo-electric array means whether or not an object is present in the apparatus for calibration of the array means prior to or during a cycle of measurement of an object. The computer may be provided with a visual display unit on which an image of an object being measured may be created indicating the measurements being taken. The image of the object shown on the V.D.U. is of limited benefit to the operator in assessing that the measurement operation is proceeding correctly and that there is no foreign body present on the object which might affect the correct measurement of the object.